1. UNIT 1 REVIEW TIER 3 Name and write the formulas for binary ionic compounds Name and write the formulas for covalent compounds Name and write the formulas for acids Apply the mole concept to substances Determine the number of particles and amount of substances (in moles) Identify the mole ratio of any two species in a chemical equation Apply the state symbols (s), (l), (g) and (aq)

2. Name and write the formulas for binary ionic compounds with: Group 1 & 2 Multivalent Polyatomic ions

3. Chapter 7 Binary Ionic Compounds Compounds composed of two elements are known as binary compounds. In a binary ionic compound, the total numbers of positive charges and negative charges must be equal. The formula for a binary ionic compound can be written given the identities of the compound’s ions. – example: magnesium bromide Ions combined: Mg 2+, Br –, Br – Chemical formula: MgBr 2 Section 1 Chemical Names and Formulas

4. Chapter 7 Binary Ionic Compounds, continued A general rule to use when determining the formula for a binary ionic compound is “crossing over” to balance charges between ions. – example: aluminum oxide 1) Write the symbols for the ions. Al 3+ O 2– 2.) Cross over the charges by using the absolute value of each ion’s charge as the subscript for the other ion Al 2 3+ O 3 2– Section 1 Chemical Names and Formulas

5. Chapter 7 Binary Ionic Compounds, continued – example: aluminum oxide, continued Al 2 3+ O 3 2– 3.) Check the combined positive and negative charges to see if they are equal (2 × 3+) + (3 × 2–) = 0 The correct formula is Al 2 O 3 Section 1 Chemical Names and Formulas

6. Chapter 7 Naming Binary Ionic Compounds The nomenclature, or naming system, or binary ionic compounds involves combining the names of the compound’s positive and negative ions. The name of the cation is given first, followed by the name of the anion: – example: Al 2 O 3 — aluminum oxide For most simple ionic compounds, the ratio of the ions is not given in the compound’s name, because it is understood based on the relative charges of the compound’s ions.

7. NAMING IONIC COMPOUNDS EXAMPLES: AgCl silver chloride CaF 2 calcium fluoride K 2 O potassium oxide NaBr sodium bromide

8. Chapter 7 Naming Binary Ionic Compounds, continued Sample Problem A Write the formulas for the binary ionic compounds formed between the following elements: a. zinc and iodine b. zinc and sulfur

9. Chapter 7 Naming Binary Ionic Compounds, continued Sample Problem A Solution Write the symbols for the ions side by side. Write the cation first. a. Zn 2+ I − b. Zn 2+ S 2− Cross over the charges to give subscripts. a.Zn 1 2+ I 2 - b.Zn 2 2+ S 2 2-

10. Chapter 7 Naming Binary Ionic Compounds, continued Sample Problem A Solution, continued Check the subscripts and divide them by their largest common factor to give the smallest possible whole-number ratio of ions. a. The subscripts give equal total charges of 1 × 2+ = 2+ and 2 × 1− = 2−. The largest common factor of the subscripts is 1. The smallest possible whole-number ratio of ions in the compound is 1:2. The formula is ZnI 2. Section 1 Chemical Names and Formulas

11. Chapter 7 Naming Binary Ionic Compounds, continued Sample Problem A Solution, continued b. The subscripts give equal total charges of 2 × 2+ = 4+ and 2 × 2− = 4−. The largest common factor of the subscripts is 2. The smallest whole-number ratio of ions in the compound is 1:1. The formula is ZnS. Section 1 Chemical Names and Formulas

12. Chapter 7 Naming Binary Ionic Compounds, continued The Stock System of Nomenclature Some elements such as iron, form two or more cations with different charges. To distinguish the ions formed by such elements, scientists use the Stock system of nomenclature. The system uses a Roman numeral to indicate an ion’s charge. – examples:Fe 2+ iron(II) Fe 3+ iron(III)

13. Chapter 7 Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem Write the formula and give the name for the compound formed by the ions Cr 3+ and F –.

14. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem Solution Write the symbols for the ions side by side. Write the cation first. Cr 3+ F − Cross over the charges to give subscripts. Cr 1 3+ F 3 −

15. Chapter 7 Section 1 Chemical Names and Formulas Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem B Solution, continued The subscripts give charges of 1 × 3+ = 3+ and 3 × 1− = 3−. The largest common factor of the subscripts is 1, so the smallest whole number ratio of the ions is 1:3. The formula is CrF 3.

16. Chapter 7 Naming Binary Ionic Compounds, continued The Stock System of Nomenclature, continued Sample Problem Solution, continued Chromium forms more than one ion, so the name of the 3+ chromium ion must be followed by a Roman numeral indicating its charge. The compound’s name is chromium(III) fluoride.

17. Chapter 7 Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions Many common polyatomic ions are oxyanions— polyatomic ions that contain oxygen. Some elements can combine with oxygen to form more than one type of oxyanion. – example: nitrogen can form NO 3 - or NO 2 - The name of the ion with the greater number of oxygen atoms ends in –ate. The name of the ion with the smaller number of oxygen atoms ends in -ite NO 3 - or NO 2 - nitrate nitrite

18. Chapter 7 Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Some elements can form more than two types of oxyanions. – example: chlorine can form ClO,ClO 2,ClO 3,or ClO 4. ClO ClO 2 ClO 3 ClO 4. hypochlorite chlorite chlorate perchlorate In this case, an anion that has one fewer oxygen atoms that the –ite anion has is given the prefix An anion that has one more oxygen atom than the –ate anion has is given the prefix per-

19. Polyatomic Ions Chapter 7 Section 1 Chemical Names and Formulas

20. Naming Compounds with Polyatomic Ions

21. Chapter 7 Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Write the formula for tin(IV) sulfate.

22. Chapter 7 Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Cross over the charges to give subscripts. Add parentheses around the polyatomic ion if necessary.

23. Chapter 7 Naming Binary Ionic Compounds, continued Compounds Containing Polyatomic Ions, continued Sample Problem Solution, continued The total positive charge is 2 × 4+ = 8+. The total negative charge is 4 × 2− = 8−. The largest common factor of the subscripts is 2, so the smallest whole-number ratio of ions in the compound is 1:2. The correct formula is therefore Sn(SO 4 ) 2.

24. Chapter 7 Naming Binary Molecular Compounds Unlike ionic compounds, molecular compounds are composed of individual covalently bonded units, or molecules. The system we use of naming molecular compounds is based on the use of prefixes. – examples:CCl 4 — carbon tetrachloride (tetra- = 4) CO — carbon monoxide (mon- = 1) CO 2 — carbon dioxide (di- = 2) Section 1 Chemical Names and Formulas

25. Prefixes for Naming Covalent Compounds Chapter 7 Section 1 Chemical Names and Formulas

26. Naming Binary Molecular Compounds continued SAMPLE PROBLEM a.Give the name of As 2 O 5 b.Write the formula for oxygen difluoride

27. SAMPLE PROBLEM continued a.A molecule of the compound contains two arsenic atoms, so the first word in the name is diarsenic The five oxygen atoms are indicated by adding the prefix pent- to the oxide. The complete name is diarsenic pentoxide Naming Binary Molecular Compounds, continued

28. Chapter 7 Naming Binary Molecular Compounds, continued Sample Problem Solution, continued b. Oxygen is first in the name because it is less electronegative than fluorine. Because there is no prefix, there must be only one oxygen atom. The prefix di- in difluoride shows that there are two fluorine atoms in the molecule. The formula is OF 2.

29. Chapter 7 Acids An acid is a certain type of molecular compound. Most acids used in the laboratory of either binary acids or oxyacids Binary acids are acids that contain only two elements, usually hydrogen and a halogen Oxyacids are acids that contain hydrogen, oxygen and a third element (usually a nonmetal.

30. NAMING A BINARY ACID For example, hydrochloric acid, HCl, consist of the prefix hydro- and the root made up of the nonmetal followed by the suffix –ic Other examples are: HFhydrofluoric acid HBrhydrobromic acid HShydrosulfuric acid

31. NAMING OXYACIDS Oxyacids contain a polyatomic ion with hydrogen. To name the acid the rule is: If the polyatomic ion ends in –ate then the ending of the acid ends in –ic If the polyatomic ion ends in –ite then the ending of the acid ends in –ous ate to ic ite to -ous EXAMPLES: HNO 3 is nitric acid HNO 2 is nitrous acid HCl0 4 is perchloric acid HClO 3 is chloric acid HClO 2 is chlorous acid HClO is hypochlorus acid